Aquariums of the type for use in containing tropical fish commonly include a layer of gravel which lines the floor of the tank. This gravel is used as a way of beautifying the aquarium, but it also has some practical purposes. It frequently serves as the foundation in which aquatic plants take root. It also serves as a colonizing area for nitrifying bacteria necessary for the conversion of fish wastes into harmless ammonia nitrates. Unfortunately, aquarium gravel can also be a major source of aquarium pollution and fish diseases, unless it is cleaned regularly. Fish wastes and uneaten food can accumulate deep within the gravel bed. Algae and other fine deposits may bond to the surface of aquarium gravel. Harmful bacteria and fish parasites may do the same. A need is apparent therefore for an effective method for removing aquarium wastes embedded within the gravel as well as on its surface.
A great deal of effort and energy has been devoted to cleaning aquarium gravel, since this is so crucial to maintaining good aquarium water quality. Prior art in cleaning aquarium aggregate is shown in a number of patents, including the following: Reyniers U.S. Pat. No. 4,610,784, the Whitman U.S. Pat. No. 4,725,353, and the Schultz U.S. Pat. No. 5,695,654.
Each of these inventions includes a gravel agitation feature. Agitation of aquarium gravel is essential for loosening debris which may be buried deep within the gravel bed. Not until the debris is separated from the gravel, can the initial phase of the gravel cleaning processes demonstrated in all of these inventions begin.
In Reyniers, gravel agitation is incorporated into the aquarium draining process through the utilization of the Venturi principle. A flexible hose is provided having opposite ends, where one end is connected to one end of a larger diameter tube. The other end of the tube is placed adjacent the gravel covering the aquarium floor. A valve and a fitting provide means for connection to the end of a faucet that contains a venturi section. When the faucet is turned on, one position of the valve causes the water running out of the faucet to draw water from the aquarium for discharge into the drain below the faucet. The outward flow of water from the gravel tube, through the flexible hose, and into the drain, is sufficient to lift some of the gravel into the tube when it is placed almost fully in contact with the gravel. But this form of syphoning action creates a relatively slow water velocity leaving the gravel tube. This rate of water flow outward from the aquarium is sufficient to carry some fish wastes embedded within gravel, but not all of it, because the outward water flow does not stimulate sufficient gravel agitation to promote the degree of gravel to gravel surface contact required for a more thorough form of gravel cleansing.
The Schultz patent takes a different approach to gravel agitation. It is reportedly the result of tests which show that separating sediment and impurities from the gravel must take place totally outside the gravel tube and in the presence of an uninterrupted flow of water up through the discharge hose. Therefore, to accomplish gravel agitation, Schultz's method includes the utilization of a frame-supported, tooth-shaped grille that has formed therein a plurality of openings to allow passage of water, sediment and impurities into the discharge hose, but not the gravel. This tooth-shaped grille, in turn, is used by the operator to manually "manipulate" the gravel about the floor of the aquarium, or cause the gravel particles to "bump and grind" against each other as a means of loosening debris imbedded within the gravel so that the debris when loosened is thereby drawn into the openings of the tooth-shaped grille and through the discharge hose before terminating into the drain.
Unfortunately, this method of gravel agitation presents its own problems. Once again, like the Reyniers method, it too incorporates the use of the Venturi principle in the aquarium draining process as a means of cleaning aquarium gravel. Granted, the Schultz method is not designed to agitate gravel by way of draining the aquarium, but it does depend on the draining process to carry fish wastes out of the tank once these wastes have been stirred up by the operator of the tooth-shaped grille. For example, in order to agitate debris-laden gravel at the bottom of an aquarium gravel bed with a depth of three or more inches, the operator of the tooth-shaped grille has a choice of either using the device to sweep away the top layers of gravel, or use the device to plow down deep inside the bed. The plowing, digging, and raking of gravel with the toothshaped grille has the potential for creating considerable cloudiness in the aquarium and thereby disturbing the inhabitants with organic pollutants, especially in aquariums that are not regularly cleaned. For best results in using this apparatus, one must exercise extreme care and patience in manipulating the grille in order to do a thorough job of cleaning the gravel while not violating the twenty-percent water volume change rule. To accomplish this feat requires traits that are not always present in those who care for aquariums.
Both Reyniers and Schultz utilize aquarium gravel cleaning approaches that wastes considerable amounts of water, since they incorporate the use of a water faucet pump which requires water flow from a faucet in order to drain the aquarium tank and thereby provide means for cleaning aquarium gravel. In fact, some pet store owners prohibit their employees from cleaning their aquariums this way because of the high water bills which may be generated in a commercial setting by using the Reyniers and Schultz's methods of aquarium gravel cleaning.
The Whitman method appears to be the closest prior art, at least in principle. It is characterized by the use of an opened bottom casing for selectively defining the boundary of a portion of gravel that is to be cleaned, and where water is pumped into the casing to achieve agitation and to dislodge and removed unwanted settled debris. A water recirculating arrangement that includes a pump, a filter, and a water discharge system within the casing is provided. The water discharge system within the casing is characterized by stationary water jets extending into the gravel at each of four corners for the purpose of gravel agitation; a rotatable member driven by water flow passing through angled outlet jets serves added agitation and dislodging purposes.
The Whitman approach differs from Reyniers and Schultz in that it does not incorporate an aquarium draining process into the process of gravel agitation or debris removal. Instead Whitman uses a pump to introduce water into the gravel casing via water jets, both rotatable and fixed, for the purpose of creating a predetermined rate of water velocity leaving the jets and thereby effectuating gravel agitation within the gravel casing. A water recirculating and filtering system acts on the same principle as ordinary aquarium power filters: utilization of pumped-induced drawing action to pull water through a filtering media and then return it to the aquarium from which it originally came.
Whitman's method of gravel agitation introduces sufficient water velocity into the gravel casing to effectively dislodge impurities embedded within the gravel without the need to incorporate an aquarium draining process into gravel agitation or gravel cleaning, like the Reyniers and Schultz inventions. While periodic aquarium draining and subsequent refilling are important as a means of diluting potentially harmful dissolved or liquid wastes, aquarium draining need not occur simultaneously as aquarium gravel agitation and cleaning. In fact, to assure water conservation and avoid violating the twenty percent aquarium water volume change rule, the draining and refilling processes should be conducted independently of the gravel agitation or gravel cleaning. There are a number of aquarium draining and refilling devices which simplify this task and are currently available through pet store dealers, or they can easily be made through the use of a single hose for syphoning water from the aquarium and using that same hose to refill the tank.
While the Whitman method offers a more focused approach toward thorough gravel agitation and cleaning than the Reyniers and Schultz methods, it does not promote the use of gravel to gravel surface contact as a means of cleaning the surface of the gravel particle. Instead, the Whitman method, with its complicated arrangement of stationary water jets extending into the gravel at each of four corners within the gravel casing and a rotatable member driven by water flow passing through angled outlet jets, merely agitates gravel for the purpose of dislodging and removing unwanted debris and impurities which have settled on top or within the gravel bed. It is not designed to harness the effective use of gravel as a means of cleansing itself. I will demonstrated how my invention utilizes this power in a far less complicated approach and why it is therefore more effective for thorough gravel particle cleansing.
Attention is also directly to the following: U.S. Pat. Nos. 4,233,702 and 4,094,788.